Kelly Rutherford sued by private eye

“Gossip Girl” star Kelly Rutherford has been hit with a lawsuit for allegedly failing to pay a private investigator for his work during her messy divorce from German businessman Daniel Giersch.

The actress endured a nightmare court battle after their 2008 split as they fought for custody over their then-2-year-old son Hermes while Rutherford was pregnant with their second child.

Professional spy Edward Banach claims he was hired in April, 2010 to keep an eye on Giersch amid allegations of child endangerment – but he was not fully compensated for the two months he spent on the case, costing just under $86,250, and he’s now getting his lawyers involved.

Banach, who was handed the job by bosses at a now-defunct security firm, is suing both Rutherford and the owners of the business for the outstanding $58,000 he alleges he’s owed, according to TMZ.com.